<!DOCTYPE html>
<html>

<head>
	<meta charset="UTF-8">
	<title>盒模型</title>
	<style type="text/css">
		.box-outer {
			border: 3px solid #286090;
			width: 270px;
		}

		.box-inner {
			border: 5px solid #f00;
			padding: 10px;
			width: 200px;
			height: 200px;
			background: #efefef;
			margin: 20px;
		}
		
		span {
			background: #ccc;
			border-radius: 5px;
			padding: 5px;
			margin: 10px;
		}
	</style>
</head>

<body>
	<div class="box-outer">
		<div class="box-inner"><span>span1</span>和<span>span2</span></div>
	</div>
</body>

</html>